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Keneba, Gambia

Darboe M.K.,MRC International Nutrition Group | Fulford A.J.C.,MRC International Nutrition Group | Secka O.,MRC Laboratories | Prentice A.M.,MRC International Nutrition Group
BMC Infectious Diseases | Year: 2010

Background: Streptococcus pneumoniae is an important cause of community acquired pneumonia, sepsis, meningitis and otitis media globally and has been incriminated as a major cause of serious childhood bacterial infections in The Gambia. Better understanding of the dynamics of transmission and carriage will inform control strategies.Methods: This study was conducted among 196 mother-infant pairs recruited at birth from six villages in the West Kiang region of The Gambia. Nasopharyngeal swabs were collected from mother-infant pairs at birth (within 12 hours of delivery), 2, 5 and 12 months. Standard techniques of culture were used to identify carriage and serotype S. pneumoniae.Results: Of 46 serotypes identified, the 6 most common, 6A, 6B, 14, 15, 19F and 23F, accounted for 67.3% of the isolates from infants. Carriage of any serotype among infants rose from 1.5% at birth to plateau at approximately 80% by 2 m (prevalence at 2 m = 77%; 5 m = 86%; 12 m = 78%). Likewise, maternal carriage almost doubled in the first 2 months post-partum and remained elevated for the next 10 m (prevalence at birth = 13%; 2 m = 24%; 5 m = 22%; 12 m = 21%). Carriage was significantly seasonal in both infants and mothers with a peak in December and lowest transmission in August. The total number of different serotypes we isolated from each infant varied and less than would be expected had the serotypes assorted independently. In contrast, this variability was much as expected among mothers. The half-life of a serotype colony was estimated to be 1.90 m (CI95%: 1.66-2.21) in infants and 0.75 m (CI95%: 0.55-1.19) in mothers. While the odds for a serotype to be isolated from an infant increased by 9-fold if it had also been isolated from the mother, the population attributable fraction (PAF) of pneumococcal carriage in infants due to maternal carriage was only 9.5%. Some marked differences in dynamics were observed between vaccine and non-vaccine serotypes.Conclusions: Colonisation of the nasopharynx in Gambian infants by S. pneumoniae is rapid and highly dynamic. Immunity or inter-serotype competition may play a role in the dynamics. Reducing mother-infant transmission would have a minimal effect on infant carriage. © 2010 Darboe et al; licensee BioMed Central Ltd. Source

Biering-Sorensen S.,Statens Serum Institute | Aaby P.,Statens Serum Institute | Napirna B.M.,Maternidade | Roth A.,Statens Serum Institute | And 5 more authors.
Pediatric Infectious Disease Journal | Year: 2012

A total of 105 low-birth-weight children presenting for first vaccination were randomized to receive bacillus Calmette-Guérin (BCG) immediately or later (current practice). The mortality rate ratio for BCG was 0.17 (95% CI = 0.02-1.35) within 3 days of enrollment, 0.28 (0.06-1.37) in the first month, and 0.27 (0.07-0.98) after 2 months of age. The mortality rate ratio was 0.41 (0.14-1.18) (P = 0.098) in infancy. Administration of BCG vaccine at first contact may contribute to lower mortality. Copyright © 2012 by Lippincott Williams & Wilkins. Source

Jensen K.J.,Statens Serum Institute | Jensen K.J.,A+ Network | Ndure J.,MRC Laboratories | Plebanskid M.,Monash University | Flanagan K.L.,Monash University
Transactions of the Royal Society of Tropical Medicine and Hygiene | Year: 2014

WHO recommends high-dose vitamin A supplementation (VAS) to children from 6 months to 5 years of age in low-income countries, in order to prevent and treat vitamin A deficiency-associated morbidity and mortality. The current policy does not discriminate this recommendation either by sex or vaccination status of the child. There is accumulating evidence that the effects of VAS on morbidity, mortality and immunological parameters depend on concomitant vaccination status. Moreover, these interactions may manifest differently in males and females. Certain vaccines administered through the Expanded Program on Immunization have been shown to alter all-cause mortality from infections other than the vaccine-targeted disease. This review summarizes the evidence from observational studies and randomized-controlled trials of the effects of VAS on these so-called heterologous or non-specific effects of vaccines, with a focus on sex differences. In general, VAS seems to enhance the heterologous effects of vaccines, particularly for diphtheria-tetanus-pertussis and live measles vaccines, where some studies, although not unanimously, show a stronger interaction between VAS and vaccination in females.We suggest that vaccination status and sex should be considered when evaluating the effects of VAS in early life. © The Author 2014. Source

Bah E.,MRC Laboratories
IARC scientific publications | Year: 2011

The national cancer registry of the Gambia was established in 1986 as part of the Gambia Hepatitis Intervention Study in collaboration with IARC, France; Medical Research Council (MRC) Laboratories of the UK; and the Government of the Gambia at MRC, Banjul. Registration of incident cancer cases is done by active and passive methods. For this study, the registry contributed data on survival for six cancer sites or types registered during 1993-1997. Follow-up has been carried out predominantly by active methods with median follow-up ranging between 1-6 months. The proportion of histologically verified diagnosis for various cancers ranged between 1-45%, and 54-82% of total registered cases were included for survival analysis. Complete follow-up at five years from the incidence date ranged between 81-98% for different cancers. The 5-year age-standardized relative survival for selected cancers were cervix (23%), non-Hodgkin lymphoma (22%), breast (10%), stomach (4%) and liver (3%). The 5-year relative survival by age group showed fluctuations with no definite pattern or trend emerging, and with no survivors in many age intervals. Source

Hill P.C.,University of Otago | Ota M.O.C.,MRC Laboratories
The Lancet Infectious Diseases | Year: 2010

The study of the contacts of patients with tuberculosis has a long history. Where tuberculosis is endemic, regular recruitment of tuberculosis cases and their household contacts can be done for research and strategic intervention. This recruitment provides a platform whereby host, pathogen, and environmental factors related to tuberculosis can be investigated and new interventions can be assessed. We describe the types of study possible within a tuberculosis case-contact study platform and its essential components, including recruitment and follow-up of the patients with tuberculosis, their household contacts and community controls, assessments and sampling, and data management and processing. Sample handling and storage, local engagement, ethical challenges, and the strengths and weaknesses of study design are all important issues in case-contact research. A case-contact study platform is a powerful research tool to answer fundamental questions in tuberculosis and has relevance to the study of other major infectious diseases. © 2010 Elsevier Ltd. Source

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